Lapidary wheel



May 1956 P. A. VONADA 2,745,225

LAPIDARY WHEEL Filed June 27, 1955 Phillip A. Vonad INVENTOR ATTORNEYUnited States Patent LAPIDARY WHEEL Phillip A. Vonada, State College,Pa.

Application June 27, 1955, Serial No. 518,247

Claims. (Cl. 51-206) The present invention relates to grinding andpolishing gemstones or the like and more particularly to a new andimproved wheel for grinding and polishing gemstones.

In the art of grinding and polishing gemstones it is the customarypractice to rigidly attach a roughly cut piece of stone to a suitableholder, known in the art as a dop stick, and by manually forcing thestone against a rotating disk-shaped abrasive wheel and adjusting theposition of the holder with respect to the working surface of .theabrasive wheel thus produce a curved surface on the stone. Such a stonehaving a curved surface is known as a cabochon. The degree of perfectionof a curved surface on such a stone is dependent upon the experience andability of the person performing the operation and, as is obvious, ahigh degree of skill is necessary to produce a desired curved surface orto produce two or more stones having substantially the same curvature orform. It is well known in the art that if during the grinding orpolishing operation the surface of the stone in contact with theabrasive wheel is allowed to become excessively hot due to the frictioncreated thereby, the stone will crack. To prevent this undesirableresult, a liquid such as water or oil is continuously applied to thesurface of the abrasive wheel, thus carrying away a substantial amountof the heat generated and keeping that part of the stone in contact withthe abrasive wheel at a safe temperature. Due to the centrifugal forceof the abrasive wheel the liquid is continuously thrown off, and meansmust be provided to catch and retain the liquid. A further disadvantageof the present art is that one must have several abrasive wheels havinga different degree of abrasiveness to perform the differentoperationssuch as grinding, sanding, polishing, et cetera, inherent in theproduction of a cabochon.

The present invention comprises a hollow or cupshaped wheel having oneor more working surfaces on the inside of the wheel and an inwardlyprotruding lip or raised portion integral with the inside forward edgeor periphery of the open end of the wheel that cooperate in a new andnovel manner and which will retain a relatively small amount of liquidwithin the wheel. The construction and use of my wheel, as will be morefully and clearly explained, provides means whereby an armate surface ona gemstone or the like may be easily and accurately formed or reproducedmerely by holding the stone against one of the working surfaces. Byprovision of the inwardly extending lip a sufficient amount of suitableliquid as may be determined by the type of wheel and the size and typeof stone being formed, may be retained within the wheel to properly coola stone being formed or polished and thus eliminate the necessity of acontinuous supply of such liquid and the associated means for catchingand retaining said liquid to prevent the operator from being splashed orinjured. By constructing my new and improved wheel of a substantiallynonabrasive material and introducing a sufficient amount of asuitablegranular abrasive mixed with a carrier such as "ice water, oil, or thelike, substantially any desirable degree of abrasiveness may be secured,said composition acting both as an abrasive and as a coolant.

An object of the present invention is the provision of a simpler,easier, cheaper, and more accurate means for producing cabochons. Asused herein, cabochon means a gemstone or the like having at least onesurface that is not fiat.

Another object is to provide a wheel for grinding an polishing whicheliminates any need for a continuous supply of liquid to the wheel aswell as the associated part or parts used or necessary to catch andretain the excess liquid. A further object of the invention is theprovision of a wheel for grinding and polishing having a plurality of 1working surfaces that cooperate in a new and novel man-- ner, thusproviding a single wheel that performs the functions of two or moreconventional wheels.

A final object of the present invention is the provision of a Wheel forgrinding and polishing whereby cabochons may be produced with accuracyand expedition and at a cost which enables them to come into extensivecommercial use.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawings in which like referencenumerals designate like parts throughout the figures thereof andwherein: m

Figure 1 shows a side view of apparatus embodying the invention, butshowing the cylindrical wheel in longi tudinal section for betterunderstanding; I

Figure 2 is a perspective view of the wheel shown in: Figure l with asection broken away;

Figure 3 shows an enlarged section of the device taken on line 33 ofFigure 2 looking in the direction of the arrows; and

Figure 4 illustrates a modification of the device.

Referring now to the drawings, wherein like reference charactersdesignate like or corresponding parts throughout the several views,there is shown in Figure 1 an electric motor 10 mounted on a base 11 andhaving a drive shaft 12 extending from one end thereof. A cylindricalwheel 13 is rigidly attached to the end of shaft 12 by means of athreaded coupling 14. Where a coupling means is used having threads as Ihave shown, it is necessary that it be threaded such that rotation ofshaft 12 will tend to tighten coupling 14 on shaft 12 to prevent thewheel from becoming disengaged from the shaft during use. However, it isto be understood that other means i may be used to couple or attachwheel 13 to shaft 12 side forward periphery. Wheel 13 may be composedofv a granular abrasive material mixed with a suitable binder of a typethat is well known in the grinding and polishing. art, or it may becomposed of a substantially non-abrasive material. In either case, Ihave found it preferable, from the point of safety, to mount the wheelin a cylindrical metal shell 18 to prevent the possibility of fractureofthe wheel while in use and consequent injury to anyone standing nearby.Use of the outer shell 18 having a back portion 20 integral therewithalso provides a rigid base on which coupling 14 may be easily mounted inany suitable and conventional manner, such as by welding, screws, or thelike.

I have also found that wheel 13' may be suitably held in shell 18 ifsaid shell 18 is shrunk onto wheel 13 "in a manner wen known in the artthus providing a good tight fit. However, if it is desirable to havewheel 13 removable or replaceable, it may be held in shell 18 byrneansofscrews, pins, or the like. As strewn in Figure 1 and Figure '2,the rear ortion has a circular flat inside working surface '19perpendicular to the longitudinal axis "of the wheel'and cylindrical'p'o'rt'ion 1 6' has a cylindrical inside 'working surf'a'c'e 21concentrie with "the longitudinal axis of the wheel. The areaof Workingsurface 19 and the degree of curvature of working surface 21aredependent on the inside diameter of the wheel which in turn may bedetermined by the-degree of curvature that it is desired to produce onone surface of "a gemstone. Obviously, if one wishes to prbduce on agemstone a convex surface having a large fadius, "a-wheel having a largeinternal diameter or radius will be necessary and if one wishes toproduce on 'a'gemstone a convex surface having a small radius, a wheelhaving a smaller'inside diameter or radius will be necessar'y.

'Therear portion 15 and the cylindrical portion 16 are joined or formedin such a manner'that a rear peripheral workin surface 22 is integralWith and joins the flat rear working surface 19 and the cylindricalworking surface 2 1, thus providing a still difierent working surfacefor operations not conveniently performed on 'saidre'ar surface 19 andcylindrical surface 21, an example of which may be the forming of aspherical surface. Working surface 22 need not necessarily be concave inform, the precise form being dependent on the surface that it isdesiredthat said working surface form, but I have found this'to be thepreferred form and where a substantially concave form is used such shapelends itself readily to increasing the ease and efliciency with whichthe interior of wheel 1'3 may be cleaned. 'Lip 17 is preferablyint'egral with the forward inside periphery of cylindrical portion 16and has an inside Working surface 23 lying in a "conical surface at anobtuse angle with surface 21, thus also lying in a conical planea't anacute angle with rrentsur'face 24. Working surface 23 and "front surface24 are joined by a convex working surface '25 having a small radius ofcurvature. It is to be noted that lip 17 may have 'a shapeother'than thepreferred form 'I'have described, such as ring shaped or the like, butI'have found that-the described form provides the maximum in strengthand utility in addition to suitably retaining a liquid "or fluid Withinthe wheel. I have'also provided a working surface 26 integral with andjoining surface 21 ands'u'rface 23, said working surface 26 having adegree of curvatureothe'r than that of surface 21 or surface'22. It willbe readily understood that surface 2 6' and surface 23 cooperate in anew and unique manner to provide different working surfaces while inaddition providing means whereby a liquid or fluid may be retainedwithin the wheel, thus eliminating the necessity of a continuous supplyof a liquid or fiuidto the wheel'and the associated parts necessary tofeed the liquid or fluid to the wheel and catch and retain the excess.It will also be readily understood that the new and novel constructionof 'my Wheel provides, in addition to the above, a plurality of workingsurfaces that cooperate in a new'and novel manner to provide a singlewheel that performs the functions of several conventional wheels inaddition to providing means whereby a gemstone or the like may be moreeasily'and accurately formed. The width of working surface 23 or, to sayit'another way, the distance that lip 17 protrudes inwardly need be onlysuch that during op eration of the Wheel an amount of liquid or fluidwillbe retained within the Wheel sufficient to cover thesu'rfa'ceof'the'stone being formed. Where the wheel provides the abrasive actionand is composed of materials well known in the art, I have found that ifa suitable liquid such as water, oil, or the like, is introduced intothe wheel in an amount sufficient to keep the surface of the stone incontact with the wheel covered at all times, said surface of reachatemperatnre 'sufiicient "to *e'atrse'it to crack or be damaged. Theprecise reason for this is not known, but it is believed that therelatively small depth of the liquid combined with its relatively largeradiating surfaces and the fact that it is being rotated is sufficientto dissipate enough heat such that the surface of the stone does notreach its critical temperature; lhave further found that where the wheelis composed of a substantially nonabrasive material and a granularabrasive medium carried by a liquid is intr'oducedvinto the wheel-to:provide the abrasive action, this fluid appears to perform the samefunction as described above thus roviding means'to form the stone andkeep it below its critical temperature. To the best of my understandingthis principle does not appear to have been fully appreciated by theprior art nor has it been applied to the grinding and polishing art andparticularly to the art of grinding and polishing gemstones. It may beWell f0 point but that in the art Of grinding and polishing metalobjects "or the like it is highly desirable that the bits of metalremoved by the abrasive not be allowed to remain in contact with theabrading surface because such will become imbedded in the surface of thewheel and materially reduce the abrasive "properties "of the wheel thusnecessitating frequent redressing of the wheel. I have found that wheremy wheelissub'stantially comprised of an abrasive material 'and used inthe manner'described herein for grinding and polishing 'gemstonesthis isnot necessarily 'the case and less frequent redressing of the wheel isnecessary. For the case where my wheeliscomprised of a substantially'non ab'rasive material and a granular abrasive material carried by aliquid is used to provide the abrading medium for grinding and polishinggemstones 'I have found that veryseldom, if ever,'is it necessaryto'redre'ss the working surfaces of mywlieel.

'Mywheel is verysimple and easy to use. For the embodiment shown inFigure l the wheel is rotated at a speedsuitableffor the type of"gemstone being formed and the type of grinding one wishes to perform.This speed varies and 'nopre'cise speed may be recommended, but I havefound thata generally suitable wheel speed is about 1100 revolutionsper'minute. It "may be further noted here that my wheel maybeused'in'thchorizontal position as shown in Figure l or it may be used in'averticaliposition. For the case where'my wheel is substantiallycomprised of an abrasive material, a suitable amount of liquid such aswater, oil, or the like, is inserted intothe'wh'eel either when it isstationary 'or when it is being rotated. In this particular instance theliquid may be of substantially any kind that will 'act as 'a'coola'nt.The centrifugal "force due to the rotation of the wheel will cause theliquid to spread out over the working surfaces, said liquid having asubstantially uniform depth. The gemstone, having previously beenattached in any conventional manner to a'suitable holder, is then heldagainst an inside working surface covered or substantially'covered bythe aforesaid liquid. If one wishes to form a convex surface on agemstone it isonly necessary to hold a surface of the stone against andperpendicular to a radius of one'of the concave-surfaces, such as, forexample, surface 21, until the desired shape is produced. A hyperbolicsurface may be easily, simply, and accurately produced by holding astone'against'surface'21 and'moving it-in'an oscillatory mannen'both tothe right 'and'to the left, through an'angle of about fortyfivedegtees-fromthe longitudinal axis of the wheel. 'If onewishes'topr'oduce a'spherical surface it is-only necessary to oscillatethe stone in a similar manner'through a similar angle er substantiallyninety degrees. If "one so desires, or "finds itmor'e convenient, a sherical surface may also be forme'd by holding the stone in the manner,previously described and continuously rotating it through an angle ofthreehundred and sixty degrees. By, simply varying the degree ofoscillation as previously described, or by simply oscillating the stonein aforwardly and rearwardly manner'with respect to theIlongi tudinalaxis of the wheel, a plurality of different surfaces may be formed. Asis now readily obvious, a plurality of arcuate surfaces may be moreeasily, quickly, and accurately produced merely by holding the stoneagainst a working surface orby holding the stone against a workingsurface and moving it in a single simplemanner. Where one wishes toproduce arcuate surfacesv on smaller stones having a radius ofcurvature-other than that of surface 21, the stone may be held, in themanner previously described, against surface 22 or surface 26. Surface22 lends itself readily; among other things, to the production ofspherical surfaces. Surface 26 lends it self readily, among otherthings, to the production on small stones of convex surfaces having arelatively large radius of curvature and surface 23is.particularly;useful in producing beveled edges or cylindricalsurfaces. If desired, surface 25 may be used to form grooves or the likein the surface of a stone and surface 19 may be used to formsubstantially flat surfaces such as the back or rear surface of agemstone. In view of the previous discussion of the methods of formingarcuate surfaces and the obviousness of the methods for forming agroove, beveled edge, fiat surface, or cylindrical surface, a preciseexplanation of the use of surfaces 19, 22, 23, 25, and 26 is notbelieved necessary for one experienced in the art.

For the case where my wheel is composed of a substantially nonabrasivesubstance such as wood, plastic, cast iron, or the like, the abrasivemedium may be supplied to the interior of the wheel in a manneridentical to that previously described for a liquid. A granular abrasivesuch as comminuted Carborundum, emery, or the like, carried in a liquidsuch as water, oil, or the like, will provide a suitable abrasive andcoolant medium. The degree of abrasiveness of this fluid may be variedby varying the size and type of granular abrasive and by varying theamount of liquid carrier. A surface of gemstone is then formed in thesame fashion and manner as that previously described for a wheelcomposed of an abrasive material.

Figure 4 shows a modification of my wheel for producing a substantiallyidentical surface on a pluralityof gemstones. Wheel 27 as shown inFigure 4 is substantially the same as wheel 13 in Figure l and Figure 2with the exception of the composition of the wheel, shell 18, and theform of working surface 21. In order to minimize the Wearing away of theworking surfaces and to keep said working surfaces substantially thesame, wheel 27 is preferably composed of cast iron or the like whichobviously obviates the necessity of a reinforcing shell 18. Since inthis case it is desired to produce a plurality of gemstones with asurface having substantially the same form or shape, a specific shapingsurface or surfaces may be formed in surface 21, examples of which areindicated by the numerals 28, 29, and 31, wherein the numeral 28indicates a convex working surface, the numeral 29 indicates a groove orworking surface forming an obtuse angle, and the numeral 31 indicates aconcave groove or working surface. More than one similar groove orsurface may be used if it is desired to form several stones at one time,or a plurality of different grooves or surfaces may be used if it isdesired to form a plurality of different surfaces at one time or withone wheel. Wheel 27 is used in substantially the same manner as thatpreviously described herein for a non-abrasive wheel with a granularabrasive materal suspended in a liquid carrier substantially aspreviously described. From the above it is obvious that substantiallyidentical surfaces may be easily and accurately produced on a pluralityof gemstones merely by holding the stone against one of the forminggrooves or surfaces until the desired surface is formed on the stone.

It will be readily understood from the foregoing description' that mynew and improved wheel provides a means whereby cabochons may be moreeasily, cheaply,

and accurately produced and that it is a self-contained unit eliminatingmany of the necessary parts associated with conventional lapidarywheels. It will be further understood that a wheel constructed accordingto the foregoing disclosure will perform the functions of a plurality ofconventional lapidary wheels in a more facile and convenient manner andthat by use of the modification described herein a plurality ofgemstones having substantially identical surfaces may be more easilyand-accurately produced.

Obviously many modifications and variations of the present-invention arepossible in the light of the above teachings. It is therefore to beunderstood, that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

I What is claimed and desired to be protected by Letters Patent of theUnited States is:

1. Means for grinding and polishing gemstones or the like comprising: ahollow cylindrical body open at one end and having a Wall closing itsother end; an inwardly protruding lip rigidly connected to the peripheryof the open end and adaptedto retain a fluid within said body; and meansconnected to said body whereby said body may be rotatably driven.

2. Means for grinding and polishing gemstones or the likecomprising: ahollow cylindrical body open at one end and having a wall closing itsother end; an inwardly protruding lip rigidly connected to the peripheryof the open end and adapted to retain a fluid within said body,

said lip having an inside surface adapted to form a substantiallyfrusto-conical working surface having its greater diameter at the baseof the lip; and means connected to said body whereby said body may berotatably driven.

3. In a hollow substantially cylindrical wheel for grinding andpolishing gemstones or the like wherein the stone is held against aninside surface the combination comprising: a substantially cylindricalportion having a front and a rear portion; a wall closing oif the rearportion and integral therewith; an inwardly protruding lip integral withthe periphery of said front portion, said lip having an inside surfaceadapted to retain a fluid within said wheel and to provide a workingsurface; and means connected to said wheel whereby said wheel may berotatably driven.

4. The combination as defined in claim 3 wherein the cylindrical wheelis comprised of an abrasive material and a suitable binder; and thefluid is a liquid adapted to act substantially as a coolant.

5. The combination as defined in claim 3 wherein the cylindrical wheelis comprised of a non-abrasive material softer than the stone beingformed; and the fluid is comprised of a granular abrasive mixed with acarrier.

6. In a hollow substantially cylindrical wheel for grinding andpolishing gemstones or the like wherein the stone is held against aninside surface the combination comprising: a substantially cylindricalportion having an inside working surface and having a front and a rearportion; a wall having an inside working surface and closing off saidrear portion; a portion having an arcuate inside working surface andintegral with said wall and said cylindrical rear portion; an inwardlyprotruding lip integral with the periphery of said front portion, saidlip having an inside surface adapted to retain a fluid within said wheeland to provide an inside working surface; an arcuate working surfacejoining said cylindrical working surface and said lip working surface;and means fixed to said wall coaxially of said wheel for connection to arotatably driven element.

7. In a non-abrasive cylindrical wheel for grinding and polishinggemstones or the like wherein the stone is held against an insidesurface and a composition comprising a granular abrasive mixed with acarrier is used as the abrading medium the combination comprising: asubface [and having a frontiandareor ipCTfi'QH; "a Wall Cl'OSing.

off the xrearpor'tion; :an inwardly protruding lip integral with theperiphery of :said frontzporition, .said ilip' liavihgv an :insidesurface adapted to retain said composition within -said'-'wheel' and 'toprovide a Working surface; and means fixed-to :said closin'g wallcoaxially of said Wheel for" connection to a ro'tatably drivenelementwhereby said composition will .be caused to cover said working'surfaces of said Wheel.

-8. The combination as defined in claim 7 comprising in addition aportion having an inside arcuate working surface and integral with thewall and the cylindrical portion; and an inside arcuate working surfaceintegral with and joining said cylindrical Working surface and said lipWorkingsurface.

9. The cotnbinationas defined in claim 7 comprising in additionaworkingrsurface formed in the inside working surface of the cylindricalportion.

10.. The combination: as Idefined zin claim 9 comprisingilliadditifinifl nma abra'sive 'cylindricaliwheelmomprisedof' al-materialiftha't is' Ia't least as hard as'the stone :being formed.

References Cited ;in'the file. of this patent UNITED "STATES PATENTS"553,225 Barnes Ian. 21, 1896 583,670 Chambers-era} June 1, 18971,262,217 rieperre Apr. '9, 1918 1,660,811 Pci'kifls Feb. 28, 19282,076,449 Doii'er Apr. 6, 1937 FOREIGN PATENTS 1, 5 28 GreaPBritain June'9, 187]. 6,978 Great Britain May '12, 1894 21,676- Great Britain Aug.27, 1914 251,167- 'Gerrna'ny June 20, 1911

